Wait is the 58th cutscene in Run 3, if counting all of the previous hidden and optional cutscenes.
This is a minor cutscene.
After beating Plan A, part 8, a short cutscene featuring the Duplicator and the Child will begin. The Duplicator is finishing off a lesson to the Child about why problems shouldn't be solved with violence. There is a short pause before the Duplicator turns around and realizes that the Child has his balloon back, after he fell off the boat with son's balloon in the cutscene Boat Ride. Surprised, the Duplicator asks the Child when he got his balloon back (even though the Child had his balloon earlier in the cutscene Fourth Condiment).